Increase in use of costly insulin analogs in type 2 diabetes

There has been a dramatic increase in use of costly insulin analogs by type 2 diabetes patients, despite the lack of evidence that they are appreciably better than human synthetic insulin, according to Yale School of Medicine researchers. Further, overall insulin use by patients with type 2 diabetes (T2D) increased by 50% in the previous decade. Their study appears in JAMA.

Insulin analogs are synthetic, molecularly altered versions of insulin that are equally effective in lowering glucose in T2D patients compared with human synthetic insulin, but much more expensive.

The researchers studied more than 123,000 patients with T2D who filled prescriptions for insulin between the years 2000 and 2010. They found that among privately insured adults in the United States, overall use of insulin among patients with T2D increased from 10% in year 2000 to 15% in 2010.

However, among those insulin users, the use of insulin analogs increased from 19% to 92% during this time. In addition, the median out-of-pocket cost per prescription for all types of insulin nearly doubled, increasing from $19 to $36 in the same time period. Although insulin analogs are supposed to reduce the risk of hypoglycemia, the authors did not find a significant decline in severe hypoglycemic events requiring a hospital visit.

“Not all patients with type 2 diabetes mellitus are likely to prefer or benefit from insulin analogs over human insulin preparations,” said first author Dr. Kasia Lipska, instructor in the Section of Endocrinology at Yale School of Medicine and Yale Center for Clinical Investigation scholar. She adds, “The rapid rate of adoption in the absence of large differences in advantages and disadvantages suggests that these decisions may have been driven by factors other than patient preference. In order to contain healthcare costs, decisions to use more expensive insulin should be made by informed patients and providers, and driven by convincing data about the benefits, harms, and tradeoffs.”